Silicone rubber-coated textiles, which were produced by coating a silicone rubber composition on a textile and curing the composition, have been used in airbags for vehicles and the like. Such a silicone rubber is required to have excellent adhesion to a textile, which serves as a base fabric of an airbag, and pliability exhibited when an airbag is deployed. In particular, internal pressure-maintaining ability of the airbag is required.
As silicone rubber compositions, for example, a silicone rubber composition formed from a diorganopolysiloxane having at least two alkenyl groups in a molecule, an organopolysiloxane resin, a silica fine powder having a specific surface area of 50 m2/g or greater, an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule, an addition reaction catalyst, an organosilicon compound having an adhesion-imparting functional group, and an organotitanium compound and/or an organozirconium compound (see Patent Document 1); a silicone rubber composition formed from an organopolysiloxane having at least two alkenyl groups bonded to silicon atom(s) in a molecule, a straight-chain organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule, an addition reaction catalyst, a silica fine powder having a specific surface area of 50 m2/g or greater, an organosilicon compound having an epoxy group and a silicon atom-bonded alkoxy group in a molecule, and a titanium compound and/or a zirconium compound (see Patent Document 2); and a silicone rubber composition formed from an organopolysiloxane having at least two alkenyl groups bonded to silicon atom(s) in a molecule, an organohydrogenpolysiloxane having at least two silicon atom-bonded hydrogen atoms in a molecule, an addition reaction catalyst, a silica fine powder having a specific surface area of 50 m2/g or greater, an organosilicon compound having an epoxy group and a silicon atom-bonded alkoxy group in a molecule, an organometal compound selected from the group consisting of organotitanium compounds, organozirconium compounds, and organoaluminum compounds, and a silane or siloxane compound having one silanol group in a molecule (see Patent Document 3) have been proposed.
In such a silicone rubber composition, typically a straight-chain organohydrogenpolysiloxane is used as the organohydrogenpolysiloxane serving as a crosslinking agent. This is because, when a resin-like organohydrogenpolysiloxane is used, it is conceived that the resulting silicone rubber becomes hard and elongation becomes small, and when a silicone rubber-coated textile is used in an airbag, the foldability thereof is reduced and pliability exhibited when the airbag is deployed is reduced.
In recent years, gas pressure supplied from an inflator becomes high, and problems occur in that the internal pressure cannot be sufficiently maintained due to openings caused by a large tension applied to the textile, which serves as the base fabric of the airbag.
As a result of diligent research, the inventors of the present invention found that openings are less likely to be formed with a silicone rubber composition including a particular organohydrogenpolysiloxane as a crosslinking agent, and thus achieved the present invention.